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Ordering Info



Path 7




Ordering Info



Design Features

  • Supports single connector axis interface including clock & direction output, encoder feedback, 2x EOT limit inputs, marker input, amplifier enable & fault, plus optional absolute encoder support
  • Features new closed-loop stepper control (pending)
  • Features one clock output (up to 25 MHz) & direction output per axis
  • Includes with 8/8 digital I/O (optically isolated), 1x high speed input


The SI4 is a part of the user-friendly Automation1 motion control platform, which includes the following:

  • Development Software
  • Controls
  • Motor Drives
  • Fiber-Optic HyperWire® Communication Bus

Complete Your Machine Control

Because the SI4 connects over Automation1’s HyperWire® network, the axes it controls can be coordinated with other axes on the network to deliver contoured motion and a single, simple machine control architecture.

Feedback Features

Each clock and direction output axis on the SI4 includes encoder feedback inputs so that you can verify accurate positioning. This input accepts incremental square-wave, absolute and (optional) incremental sine-wave encoder signals.  

The dedicated axis feedback signals include encoder feedback (sine +/-, cosine +/- & marker inputs), 2x end of travel (EOT) limit switch inputs and amplifier enable and fault I/O. A dedicated digital I/O port supports 8 digital inputs, 8 digital outputs (sourcing or sinking) and 1 differential high-speed input. 

Platform Power

More than just hardware, the SI4 gives you access to the complete power of the Automation1 motion control platform. This includes the Automation1 motion development kit (MDK), the intelligent software-based controller (iSMC) and the powerful AeroScript programming language with integrated RS-274 G and M code support. The Automation1 iSMC can also be programmed by various controller APIs, which provide flexible methods of integrating the SI4 and the axes it controls into your system architecture.    

SI4 Specifications

HyperWire Communication 2x HyperWire small form-factor pluggable (SFP) ports
Control Output Supports two or four axes of stepper clock & direction control
Control Supply Voltage: 24 VDC

Current, 2 Axis Unit: 2 A max, 0.45 A typical

Current, 4 Axis Unit 2 A max, 0.6 A typical
User Power Supply Output 5 VDC
Modes of Operation Open loop

Closed loop (Pending)
Protective Features Output short circuit

Control power supply undervoltage
25-Pin Axis Connector Stepper clock & direction output

High-speed differential inputs (encoder sin, cos and marker)

Absolute encoder interface (support optional)

CW and CCW limits

5 VDC power supply

Amplifier enable and fault.
Digital I/O Connector 8x optically isolated digital inputs (externally powered, 5-24 VDC)

8x optically isolated digital outputs (externally powered, 5-24 VDC)

1x optically isolated high-speed inputs

1x 5 VDC power supply
Drive Array Memory 16.7 MB (4,194,304 32-bit elements)
High Speed Data Capture Yes (50 ns latency)
Automatic Brake Control Assignable digital output
E-Stop Sense Input Assignable digital input
Absolute Encoder (Optional) BiSS C Unidirectional; EnDat 2.1; EnDat 2.2
Position Command Update Rate 20 kHz
Operating Temperature 0 to 40 °C
Storage Temperature -30 to 85 °C
Weight 0.59 kg (1.30 lb)
Compliance CE approved, Follows EU 2015/863 RoHS 3 directive


Automation1 SI4-2P1

Automation1 SI4-4P1

Automation1 SI4-2P2

Automation1 SI4-4P2

Ordering Information

Automation1 SI4

Option Description
Automation1 SI4Automation1 SI4 Stepper Controller

Peak Current

Option Description
-2P1 2 Axes of Control, Standard Packaging
-2P2 2 Axes of Control, OEM Packaging
-4P1 4 Axes of Control, Standard Packaging
-4P2 4 Axes of Control, OEM Packaging

Absolute Encoder

Option Description
-A0 No Absolute Encoder Support (default)
-A1 Absolute Encoder Support